1. Field of the Invention
The present invention relates to a scouring system for automatically scouring a liquid reservoir which has been emptied, particularly a flood basin or a reservoir in a channel or sewer system. The scouring system includes at least one scouring liquid chamber arranged in the area of the highest point of the floor of the liquid reservoir. The scouring liquid chamber has a ceiling which closes the chamber in an air-tight manner. The scouring liquid chamber further has a scouring opening which is a siphon-like flow duct with an inlet opening facing the scouring liquid chamber and an outlet opening facing the liquid reservoir. The upper edge of the inlet opening is located below the lower edge of the outlet opening. The scouring liquid chamber has an outlet opening for air to be displaced during filling of the scouring liquid chamber. A check valve is provided at the air outlet opening of the scouring liquid chamber. The scouring liquid chamber further has an air inlet opening with a valve seat which can be closed by means of a valve member and can be released by the valve member for initiating a scouring procedure.
2. Description of the Related Art
In a scouring system of the above-described type disclosed in DE 39 15 076 C2, a pipe piece is arranged in the ceiling which closes the scouring liquid chamber in an air-tight manner. The pipe piece has an outlet opening for the air to be displaced during the filling of the scouring liquid chamber with scouring liquid and an air inlet opening. The outlet opening is provided with a check valve. The air inlet opening has a valve seat for a valve member for closing the air inlet opening and for releasing the air inlet into the scouring liquid chamber, wherein the valve member is connected to a float gauge in such a way that the float gauge and valve member move together.
This arrangement and the particular configuration of the outlet zone of the scouring liquid chamber make it possible that the scouring liquid is held back in the scouring liquid chamber not directly by mechanical closing means, such as flaps which close the scouring openings, but indirectly by atmospheric pressure which becomes effective automatically when the liquid level in the reservoir is lowered. The scouring procedure is effected by releasing the air inlet in the scouring liquid chamber.
Accordingly, the above-described known scouring system makes it possible to operate essentially without moving parts arranged below the level of the reservoir liquid which are subjected to the danger of contamination. However, the operation of the known scouring system is still not entirely secure because of the actuation of the valve member for the air inlet opening by means of a float gauge which requires that the filling of the scouring liquid chamber is dependent on the simultaneous filling of the reservoir.